In a previous article about the tar program I mentioned gzip and bzip2 compression methods as options to create a tarball (and I forgot xz).
To make amends today I will introduce the main methods to compress the file and I’ll do some tests to see how they behave.

I will consider zip, gzip, bzip2 and xv, i will not test compress another compression program present on Linux systems but now dated and surpassed by the other programs.
But as first thing an overview of these 4 methods/programs of compression